A note on negative thermal expansion coefficients

1962 ◽  
Vol 23 (4) ◽  
pp. 425-427 ◽  
Author(s):  
M.J. Klein ◽  
R.D. Mountain
Keyword(s):  
Thermal Expansion ◽  
Negative Thermal Expansion ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

Negative Thermal Expansion of Yb2Mo3O12 and Lu2Mo3O12

2008 ◽  
Vol 368-372 ◽  
pp. 1662-1664 ◽  
Author(s):  
X.L. Xiao ◽  
M.M. Wu ◽  
J. Peng ◽  
Y.Z. Cheng ◽  
Zhong Bo Hu
Keyword(s):  
Thermal Expansion ◽  
Solid State ◽  
Solid State Reaction ◽  
Linear Thermal Expansion ◽  
Negative Thermal Expansion ◽  
Orthorhombic Structure ◽  
Conventional Solid State Reaction ◽  
Temperature Range ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

Compounds Yb2Mo3O12 and Lu2Mo3O12 were prepared by conventional solid-state reaction. Their crystal structures and thermal expansion properties were investigated. It was found that Yb2Mo3O12 and Lu2Mo3O12 adopt orthorhombic structure and show negative thermal expansion (NTE) in the temperature range of 200-800 °C. Their a-axis and c-axis exhibit stronger contraction in the temperature range of 200-800 °C, while b-axis slightly expands in the temperature range of 200-300 °C and then contracts in the temperature range of 300-800 °C. The linear thermal expansion coefficients al of Yb2Mo3O12 and Lu2Mo3O12 are −5.17 × 10−6 °C−1 and −5.67 × 10−6 °C−1, respectively.

scholarly journals Thermal expansion coefficient of few-layer MoS2 studied by temperature-dependent Raman spectroscopy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhongtao Lin ◽  
Wuguo Liu ◽  
Shibing Tian ◽  
Ke Zhu ◽  
Yuan Huang ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Negative Thermal Expansion ◽  
Thermal Parameter ◽  
Temperature Dependent ◽  
Bending Vibrations ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

AbstractThe thermal expansion coefficient is an important thermal parameter that influences the performance of nanodevices based on two-dimensional materials. To obtain the thermal expansion coefficient of few-layer MoS2, suspended MoS2 and supported MoS2 were systematically investigated using Raman spectroscopy in the temperature range from 77 to 557 K. The temperature-dependent evolution of the Raman frequency shift for suspended MoS2 exhibited prominent differences from that for supported MoS2, obviously demonstrating the effect due to the thermal expansion coefficient mismatch between MoS2 and the substrate. The intrinsic thermal expansion coefficients of MoS2 with different numbers of layers were calculated. Interestingly, negative thermal expansion coefficients were obtained below 175 K, which was attributed to the bending vibrations in the MoS2 layer during cooling. Our results demonstrate that Raman spectroscopy is a feasible tool for investigating the thermal properties of few-layer MoS2 and will provide useful information for its further application in photoelectronic devices.

Designing Microstructural Architectures With Thermally Actuated Properties Using Freedom, Actuation, and Constraint Topologies

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Jonathan B. Hopkins ◽  
Kyle J. Lange ◽  
Christopher M. Spadaccini
Keyword(s):  
Thermal Expansion ◽  
Bulk Material ◽  
Negative Thermal Expansion ◽  
Element Analysis ◽  
Thermal Expansion Coefficients ◽  
Design Requirements ◽  
Expansion Coefficients ◽  
Thermally Actuated ◽  
Constraint Topologies

In this paper, we demonstrate how the principles of the freedom, actuation, and constraint topologies (FACT) approach may be applied to the synthesis, analysis, and optimization of microstructural architectures that possess extreme or unusual thermal expansion properties (e.g., zero or large negative-thermal expansion coefficients). FACT provides designers with a comprehensive library of geometric shapes, which may be used to visualize the regions wherein various microstructural elements can be placed for achieving desired bulk material properties. In this way, designers can rapidly consider and compare a multiplicity of microstructural concepts that satisfy the desired design requirements before selecting the final concept. A complementary analytical tool is also provided to help designers rapidly calculate and optimize the desired thermal properties of the microstructural concepts that are generated using FACT. As a case study, this tool is used to calculate the negative-thermal expansion coefficient of a microstructural architecture synthesized using FACT. The result of this calculation is verified using a finite element analysis (FEA) package called ale3d.

THERMAL EXPANSION OF ZrO2-ZrW2O8 COMPOSITES PREPARED USING CO-PRECIPITATION ROUTE

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1449-1454 ◽  
Author(s):  
HONGFEI LIU ◽  
ZHIPING ZHANG ◽  
XIAONONG CHENG ◽  
JUAN YANG
Keyword(s):  
Thermal Expansion ◽  
Negative Thermal Expansion ◽  
Ceramic Composites ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Co Precipitation ◽  
Scanning Electron

In this work, a series of ZrO 2/ ZrW 2 O 8 ceramic composites with different amounts of ZrW 2 O 8 were successfully prepared by calcining the precursors synthesized using co-precipitation route at 1150°C for 3 h. The X-ray diffraction (XRD) data confirmed that the composites only consisted of α- ZrW 2 O 8 phase and m - ZrO 2 phase. The scanning electron microscopy (SEM) analysis of the synthesized ZrO 2/ ZrW 2 O 8 composites showed that the specimens had good mixed-uniformities. In addition, the thermal expansion coefficients of the composites decreased with increased amounts of negative thermal expansion ZrW 2 O 8, specimen with 26wt% ZrW 2 O 8 shows almost zero thermal expansion and its average thermal expansion coefficient is -0.5897×10-6K-1 in the temperature range from 30°C to 600°C.

Coprecipitation Synthesis and Negative Thermal Expansion of R2Mo3O12 (R = Y, Yb)

2009 ◽  
Vol 79-82 ◽  
pp. 1567-1570 ◽  
Author(s):  
Hai Tao Yang ◽  
Wei Lin Lin ◽  
Fu Liang Shang ◽  
Yuan Hui Huang ◽  
Ling Gao
Keyword(s):  
Thermal Expansion ◽  
Negative Thermal Expansion ◽  
Xrd Analysis ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
High Temperature Xrd ◽  
Coprecipitation Synthesis ◽  
Expansion Coefficients

In this research, powders of Y2Mo3O12 and Yb2Mo3O12 were successfully synthesized by liquid phase coprecipitation, followed with a heat treatment at 750°C for 6h. X-ray diffraction (XRD) analysis indicated that the Y2Mo3O12 and Yb2Mo3O12 were single orthorhombic structure with the space group of Pbcn. Negative thermal expansion properties of Y2Mo3O12 and Yb2Mo3O12 were studied with high temperature XRD analysis. The thermal expansion coefficients of Y2Mo3O12 and Yb2Mo3O12 were calculated to be -5.943×10-6K-1 and -6.237×10-6K-1 respectively.

Thermal Expansion of Anti-Perovskite Mn3Zn1-xSnxN Compounds

2012 ◽  
Vol 512-515 ◽  
pp. 890-893 ◽  
Author(s):  
Xue Hua Yan ◽  
Jia Qi Liu ◽  
Zhu Yuan Hua ◽  
Bing Yun Li ◽  
Xiao Nong Cheng
Keyword(s):  
Thermal Expansion ◽  
Negative Thermal Expansion ◽  
Cubic Crystal ◽  
Thermal Expansion Behavior ◽  
Sn Doping ◽  
Thermal Expansion Coefficients ◽  
Expansion Behavior ◽  
Expansion Curve ◽  
Wide Perspective ◽  
Expansion Coefficients

The anti-perovskite structured Mn3XN(X=Cu,Al,Ag,Zn,Ga,Sn,In) have wide perspective and practicability with unique advantages compared with other materials as a new negative thermal expansion (NTE) material. Because of its simple preparation and unique properties of NTE, this kind of compounds aroused scientists’ attention. The metallic nitrides Mn3Zn1-xSnxN (x=0.1, 0.2, 0.3, 0.4, 0.5) were prepared by solid-state sintering. The anti-perovskite compound Mn3Zn1-xSnxN has a cubic crystal structure with space group Pm3m. It shows that Zn element is partial replaced by Sn element. The Sn doping in Mn3Zn1-xSnxN compound can cause the thermal expansion behavior of the compound to change between positive and negative by analyzing the curve of thermal expansivity with the temperature. Mn3Zn0.7Sn0.3N shows a very strong NTE. Its negative thermal expansion coefficients were -4.39×10-4/K from 345.4 °C to 476.2 °C. In addition, the variation of the thermal expansion curve for Mn3Zn0.8Sn0.2N is almost negligible with the increasing of temperature to 600 °C, exhibiting nearly zero thermal expansion behavior. Therefore, the thermal expansion of Mn3Zn1-xSnxN could be tuned via different contents of Sn in Mn3ZnN.

Synthesizing the Compliant Microstructure of Thermally Actuated Materials Using Freedom, Actuation, and Constraint Topologies

2012 ◽  
Author(s):  
Jonathan B. Hopkins ◽  
Kyle J. Lange ◽  
Christopher M. Spadaccini
Keyword(s):  
Thermal Expansion ◽  
Screw Theory ◽  
Bulk Material ◽  
Negative Thermal Expansion ◽  
Thermal Expansion Coefficients ◽  
Final Design ◽  
Expansion Coefficients ◽  
Thermally Actuated ◽  
Constraint Topologies

The aim of this paper is to demonstrate how the principles of the Freedom, Actuation, and Constraint Topologies (FACT) synthesis approach may be applied to the design of compliant microstructural architectures that possess extreme or unusual thermal expansion properties (e.g., zero or large negative thermal expansion coefficients). FACT provides designers with a comprehensive library of geometric shapes, which may be used to visualize the regions wherein various microstructural elements can be placed for achieving desired bulk material properties. In this way, designers can rapidly consider and compare every microstructural concept that best satisfies the design requirements before selecting the final design. A screw-theory-based analytical tool is also provided in this paper to help designers calculate and optimize the thermal properties of microstructural concepts, which are generated using FACT. As a case study, this tool is used to calculate the negative thermal expansion coefficient of a microstructural architecture synthesized using FACT.

scholarly journals A system with adjustable positive or negative thermal expansion

2007 ◽  
Vol 463 (2082) ◽  
pp. 1585-1596 ◽  
Author(s):  
Joseph N Grima ◽  
Pierre S Farrugia ◽  
Ruben Gatt ◽  
Victor Zammit
Keyword(s):  
Thermal Expansion ◽  
Thermal Properties ◽  
Negative Thermal Expansion ◽  
Two Dimensional ◽  
Practical Applications ◽  
Anisotropic Thermal Expansion ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

We analyse the anisotropic thermal expansion properties of a two-dimensional structurally rigid construct made from rods of different materials connected together through hinges to form triangular units. In particular, we show that this system may be made to exhibit negative thermal expansion coefficients along certain directions or thermal expansion coefficients that are even more positive than any of the component materials. The end product is a multifunctional system with tunable thermal properties that can be tailor-made for particular practical applications.

scholarly journals A five-fold interpenetrated metal–organic framework showing a large variation in thermal expansion behaviour owing to dramatic structural transformation upon dehydration–rehydration

2017 ◽  
Vol 53 (5) ◽  
pp. 861-864 ◽  
Author(s):  
Himanshu Aggarwal ◽  
Raj Kumar Das ◽  
Emile R. Engel ◽  
Leonard J. Barbour
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Metal Organic Framework ◽  
Negative Thermal Expansion ◽  
Considerable Change ◽  
Thermal Expansion Coefficients ◽  
Thermal Expansion Behaviour ◽  
Metal Organic ◽  
Expansion Coefficients ◽  
Expansion Behaviour

A five-fold interpenetrated MOF has the highest uniaxial negative thermal expansion coefficient reported for any interpenetrated MOF to date. Upon dehydration, the framework shows considerable change in the magnitudes of the thermal expansion coefficients.

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